GraphQL Node教程第7步遇类型重定义等语法错误，求指导

Hey there! Let's break down your issues step by step to get you back on track with the GraphQL subscriptions chapter:

1. Fixing the "Redefining Type" Error #

The root cause of those duplicate type errors is straightforward:
You've defined User, Link, and Vote in both your datamodel.prisma and Schema.graphql files. Prisma automatically generates a GraphQL schema (usually in generated/prisma-client/schema.graphql) based on your datamodel. When you run your server, it tries to merge this generated schema with your custom Schema.graphql—and hits conflicts because the types exist twice.

Solution: #

Remove the duplicate type definitions from your Schema.graphql. You only need to keep your custom operations (queries, mutations, subscriptions) and any extra types/enums you've added (like Feed, AuthPayload, and LinkOrderByInput). Here's what your cleaned-up Schema.graphql should look like:

type Query {
  info: String!
  feed(filter: String, skip: Int, first: Int, orderBy: LinkOrderByInput): Feed!
}

type Feed {
  links: [Link!]!
  count: Int!
}

type AuthPayload {
  token: String
  user: User
}

type Subscription {
  newLink: Link
  newVote: Vote
}

type Mutation {
  post(url: String!, description: String!): Link!
  signup(email: String!, password: String!, name: String!): AuthPayload
  login(email: String!, password: String!): AuthPayload
  vote(linkId: ID!): Vote
}

enum LinkOrderByInput {
  description_ASC
  description_DESC
  url_ASC
  url_DESC
  createdAt_ASC
  createdAt_DESC
}

2. Are Your Directives & Scalars in datamodel.prisma Correct? #

Absolutely! Those directives and scalars are part of Prisma's datamodel syntax (not standard GraphQL), and they're working exactly as intended:

• @id: Marks a field as the primary key for the database model
• @unique: Enforces a unique constraint on the field in the database
• @createdAt: Automatically sets the field to the timestamp when the record is created (you never need to manually assign this value)
• DateTime: A Prisma-provided scalar that maps to date/time types in your database

The official tutorial might not explicitly cover these because they're standard Prisma configuration—you're using them correctly here.

3. Quick Post-Fix Checks #

To make sure everything works smoothly:

• Run prisma generate in your terminal to refresh the generated Prisma client and schema
• Double-check your server code is merging the Prisma-generated schema with your custom Schema.graphql (most setups use mergeSchemas or pass an array of typeDefs to Apollo Server)
• Restart your GraphQL server and test the subscriptions functionality

内容的提问来源于stack exchange，提问作者jackdaw